1. Field of the Invention
The present invention relates to a hard disk drive, and more particularly, to a hard disk drive with a damping element attenuating vibration during operation of the hard disk drive.
2. Description of the Related Art
A hard disk drive is an auxiliary memory unit used in a computer, in which data is read from a magnetic disk and/or new data is written to the magnetic disk by use of a magnetic head. There has been increasing demand for a hard disk drive with a high speed, a high capacity and a low vibration, and several developments have been made to satisfy this demand.
FIG. 1 is an exploded view a conventional hard disk drive. Referring to FIG. 1, the hard disk drive 10 includes a disk 15, a spindle motor 20 to turn the disk 15 the spindle motor 20 being connected to a base 11, an actuator 30 supporting a magnetic read/write head 45 writing the data to the disk 15 and/or reading the data from the disk 15, and a cover 12 fastened to the base 11 that covers and protects components inside the hard disk drive 10.
The disk 15 is secured to a rotator of the spindle motor 20, and turns with respect to the base 11. On a surface of the disk 15, data indicating a position of the data to be written are previously recorded in tens of thousands of tracks formed along a circumference of the disk 15.
The actuator 30 is rotated around a pivot bearing 33 connected to the base 11 by a voice coil motor 32. The actuator 30 includes an arm 35 rotatably coupled to the pivot bearing 33, and a head gimbal assembly (HGA) 37 connected to the arm 35 supporting and biasing a slider 40, on which the magnetic head 45 is mounted, toward the surface of the disk 15.
When the disk 15 in the hard disk drive 10 is rotated, a lift force is generated in the hard disk drive by air pressure. The slider 40 is maintained in a floating state on the surface of the disk at a height at which the lift force generated by the rotation of the disk 15 is in equilibrium with an elastic force of the HGA 37. Accordingly, the magnetic head 45 mounted on the slider 40 is spaced a predetermined distance from the rotating disk 15 to write and/or read the data to and/or from the disk 15.
In the conventional hard disk drive 10, there may be vibration due to a structural characteristic or defect of the spindle motor 20, eccentricity of the disk 15, irregular air flow in the hard disk drive 10, etc. The vibration adversely affects a position error signal (PES) and a write/read error of the magnetic head 45, and increases noise, thereby deteriorating reliability of the hard disk drive.
To decrease vibration due to structural characteristics, a hydrodynamic bearing has been used in the spindle motor 20 of the hard disk drive. The spindle motor employing the hydrodynamic bearing can rotate the disk 15 at a high speed above 7200 rpm. When the disk 15 rotates at a high speed, air flow rotating in the same direction as the rotational direction of the disk as indicated by an arrow D is a major factor causing the disk 15, the actuator 30 and the hard disk drive 10 to vibrate. It is necessary to control the air flow rotating in the direction of arrow D to decrease the vibration of the disk 15, the actuator 30 and the hard disk drive 10 and thus improve the reliability of the hard disk drive.